In recent years, the petroleum industry has invested heavily in the development of improved seismic survey techniques and seismic data processing methods in order to increase the resolution and accuracy of seismic images of subterranean formations. Seismic surveys illuminate a subterranean formation with sound waves produced by one or more seismic sources. As a sound wave travels down into the subterranean formation, at each interface between different types of rock or sediment a portion of the sound wave is refracted, a portion is transmitted, and a portion is reflected back toward the formation surface where seismic receivers positioned above the subterranean formation detect reflected wavefields. Subsurface illumination with acoustic impulses often depends on the survey acquisition geometry used to collect the seismic data and the selected seismic imaging technique. Different offset ranges in narrow-azimuth surveys and offset and azimuth ranges in wide-azimuth and full-azimuth surveys are used to create different illuminations of the subterranean formation.
Isotropic and anisotropic pre-stack imaging algorithms are often used to generate image gathers of a subterranean formation from the reflected wavefield data. Image gathers may be stacked in order to reduce noise in subsequently generated seismic images of the subterranean formation. However, many currently used stacking techniques, such as straight stacking, are not optimal for stacking image gathers of subterranean formations with deposits of materials that create anomalous changes in velocities of acoustic waves used to illuminate the subterranean formation. Examples of these deposits include salt domes, mobile shales, carbonates, and/or basalt bodies. Acoustic illumination of a subterranean formation with these types of deposits often results in seismic images with gaps or zones of poor image quality below or within the deposits. As a result, identifying a hydrocarbon reservoir located below these deposits in seismic images generated by typical seismic data processing techniques remains a challenge. Those working in petroleum exploration and seismic data processing continue to seek systems and methods for improving seismic image quality of subterranean formations that have a wide variety of deposits and irregular-shaped formations.